Mutagenesis analysis of CaMKII translocation to microtubules. (A) Mean (±SEM) ΔF/F₀ of GCaMP2 and (B) mean (±SEM) fold increase in mGFP-αCaMKII microtubular translocation (normalized to control without shRNA) with or without coexpression of shRNA against α- and βCaMKII isoforms during a 1-min KCl stimulation. n = 17–18 neurons (A) and 5 neurons (B) per condition. *, P < 0.05 unpaired t test. (C) Neurons transfected with shRNA against α- and βCaMKII and expressing different shRNA-resistant GFP-CaMKII mutants, before and during a 1-min stimulation with KCl. White arrows point to detectable fibers in CaMKII signal. Bar, 10 µm. (D) Fold increase in microtubular translocation during the KCl stimulation for various mutants. (n = 6–24 neurons per condition, 4 experiments; asterisk indicates different from GFP). (E) Fold increase in the microtubular translocation during a 1-min KCl stimulation with or without KN drugs. (Vehicle: 0.1% DMSO; n = 13–18 neurons per condition, 3 experiments; asterisk indicates different from vehicle). *, P < 0.05 Kruskal-Wallis followed by Tukey’s least-significant difference test. See also Fig. S4.